How Do Igneous Rocks Form - Internet Activity printable pdf download

How Do Igneous Rocks Form - Internet Activity

NAME _____________________________ DATE __________________ CLASS ______________

How do Igneous Rocks form?

– Internet Activity

short description

1.Observe each rock shown. Write a

for each one

. (Page 1)

Samples

Description

Identify the texture of each igneous rock as coarse grained, fine-grained or porphyritic.

(Pages 2-3)

Page 2

Sample 1

Sample 2

Sample 3

Sample 4

Page 3

Sample 5

Sample 6

Sample 7

. (Use what you know about igneous rocks.)

3. Match the term to the best definition

____ A coarse-grained rock contains minerals grains that are

a. a mixture of fine and coarse-

grained minerals

_____ A fine-grained rock contains mineral grains that are

b. visible to the naked eye

_____ A porphyritic rock contains mineral grains that are

c. to small to see without a

microscope

4. Scroll over the image and click on the different links to see a visualization of how igneous rocks cool.

(Page 5)

(Page 6)

5. Cooling Rate and Environment

First, determine if the sample has crystals or not (click on each image to enlarge



Next identify the cooling rate (fast, slow, or 2-staged porphyritic).



Finally, decide what the cooling environment was (intrusive, extrusive, or deep cooling after eruption.)

